Automatic Uplink Power Control (Aupc); Doubletalk Carrier- In-Carrier - Comtech EF Data CDM-625 Installation And Operation Manual

CDM-625 Advanced Satellite Modem
Introduction
1.4.4

Automatic Uplink Power Control (AUPC)

Operating Mode
Target Eb/No range
Max AUPC range
Monitor functions
1.4.5 DoubleTalk
Operating Mode
Power Spectral Density Ratio and
CnC Ratio
Maximum Symbol Rate Ratio
Inbound/Outbound frequency
uncertainty
Delay range
Eb/No Degradation
(equal Inbound/Outbound power
spectral density)
Monitor Functions
CnC Monitor Accuracy
Requires Closed Network Framed mode (EDMAC, D&I++, Enhanced D&I, or ESC++) for transport of
Eb/No information from remote modem (EDMAC can be enabled or disabled)
0 to 14.9 dB at remote demod (default is 4.0 dB)
0 to 9 dB (default is 3 dB)
Remote demod Eb/No
Tx power level increase
(front panel or via remote control interface)
®
Carrier- in-Carrier
Requires the two links to share a common carrier frequency (Outbound and Inbound symbol rates do
not have to be equal)
BSPK/QPSK/8PSK/8-QAM: –7 dB to +11 dB (ratio of power spectral density, outbound interferer to
desired inbound)
16-QAM: –7 dB to +7 dB (ratio of power spectral density, outbound interferer to desired inbound)
Note: With asymmetric carriers, the absolute power ratio (or CnC ratio) would be different,
depending on the ratio of the symbol rates.
Example:
Outbound interferer = 1 Msymbols/sec
Desired Inbound = 500 ksymbols/sec
Ratio of power spectral density = +7 dB
Absolute power ratio (CnC Ratio) = +7dB + (10 log Outbound/desired symbol rate) = +10 dB
3:1 (TX:RX or RX:TX)
Within the normal acquisition range of the demod, as follows:
Below 64 ksymbols/sec: ±1 to ± (Rs/2) kHz, where Rs = symbol rate in ksymbols/sec
Between 64 and 389 ksymbols/sec: ± 1up to a maximum of ± 32kHz
Above 389 ksymbols/sec: ±1 to ± (0.1Rs) kHz, up to a maximum of ± 200 kHz
0-330 ms
BPSK = 0.3dB QPSK = 0.3dB
8PSK = 0.5dB 8-QAM = 0.4dB 16-QAM = 0.6dB
For +10 dB power spectral density ratio (outbound interferer 10 dB higher than desired inbound) add
an additional 0.3 dB
Delay, in milliseconds
Frequency offset (between outbound interferer and desired inbound). 100 Hz resolution
CnC Power Ratio, in 0.1 dB (ratio of absolute power, outbound interferer to desired inbound)
Power Spectral Density Ratio, in 0.1 dB
±0.1 dB for symmetric symbol rate
®
(CnC)
OQPSK = 0.3dB
1–22
Revision 13
MN-CDM625